I'm sorry you are hurt though. You are right to be upset because she's witholding information from you that can affect your physical health. She's making decision without including you in the process.

I wrote this in response to a thread similar thread about a partner plunging onward without consult listing some rights and responsibilities.

If she's new to poly, she may not be acting with malice, but you guys need to get the rights and responsibilities to each other down and get with it on the communication.

So play ball. Try to chill on the upset and not blast her with it (you have every right to be mad but it just sidetracks the convo elsewhere into a blackhole of energy waste.)

You hold up YOUR responsibility to know and state your needs, wants and limits.

You give her HER right to constructive feedback (positive or negative. Critique, not criticism.)

state your needs, wants:

Praise the heads up for going on the date before the date happened. That part was good. You need to know the heads up before it happens and there she delivered. Yay. You felt important to her and valued and respected as one of her partners. Because of that you could let go of anxiety and open yourself up to feeling happy for her on her date. Yay compersion. Yay for all. Nobody caught off guard. This is kindness to partner.

constructive feedback :

Not as yay on the sex news delivery. That came after the fact. You need to know BEFORE. Esp sex health info because that affects your own sex health. When she sleeps with someone, you are sleeping with them too. So... play ball and play fair here. Does she find this request reasonable? To tell before hand? Because when she does not tell before hand you feel unimportant to her and not valued as a partner. Totally caught off guard, and now worried about sex health. Not nice feeling. This is not kindness to partner.